From f8da4b5155ed9a639ee4250746b5f7ffa6302bf6 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 24 Sep 2016 00:34:57 +0900 Subject: [PATCH] perf probe: Ignore the error of finding inline instance Ignore the error when the perf probe failed to find inline function instances. This can happen when we search a method in C++ debuginfo. If there is completely no instance in target, perf probe can return an error. E.g. without this fix: ---- $ perf probe -x /usr/lib64/libstdc++.so.6 -vD showmanyc probe-definition(0): showmanyc symbol:showmanyc file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments symbol:catch file:(null) line:0 offset:0 return:0 lazy:(null) symbol:throw file:(null) line:0 offset:0 return:0 lazy:(null) symbol:rethrow file:(null) line:0 offset:0 return:0 lazy:(null) Open Debuginfo file: /usr/lib/debug/usr/lib64/libstdc++.so.6.0.22.debug Try to find probe point from debuginfo. Matched function: showmanyc An error occurred in debuginfo analysis (-2). Trying to use symbols. Failed to find symbol showmanyc in /usr/lib64/libstdc++.so.6.0.22 Error: Failed to add events. Reason: No such file or directory (Code: -2) ---- This is because one of showmanyc is defined as inline but no instance found. With this fix, it is succeeded to show as below. ---- $ perf probe -x /usr/lib64/libstdc++.so.6 -D showmanyc p:probe_libstdc++/showmanyc /usr/lib64/libstdc++.so.6.0.22:0xb0e50 p:probe_libstdc++/showmanyc_1 /usr/lib64/libstdc++.so.6.0.22:0xc7c40 p:probe_libstdc++/showmanyc_2 /usr/lib64/libstdc++.so.6.0.22:0xecfa0 p:probe_libstdc++/showmanyc_3 /usr/lib64/libstdc++.so.6.0.22:0x115fc0 p:probe_libstdc++/showmanyc_4 /usr/lib64/libstdc++.so.6.0.22:0x121a90 ---- Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Tested-by: Jiri Olsa Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/147464489775.29804.3190419491209875936.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-finder.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 8daca4fc1f8d..5fe8325e81f2 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -988,7 +988,8 @@ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data) if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die))) return DWARF_CB_OK; - pr_debug("Matched function: %s\n", dwarf_diename(sp_die)); + pr_debug("Matched function: %s [%lx]\n", dwarf_diename(sp_die), + (unsigned long)dwarf_dieoffset(sp_die)); pf->fname = dwarf_decl_file(sp_die); if (pp->line) { /* Function relative line */ dwarf_decl_line(sp_die, &pf->lno); @@ -1011,7 +1012,7 @@ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data) param->retval = die_walk_instances(sp_die, probe_point_inline_cb, (void *)pf); /* This could be a non-existed inline definition */ - if (param->retval == -ENOENT && strisglob(pp->function)) + if (param->retval == -ENOENT) param->retval = 0; }